The Higgs boson has been nicknamed the God particle as it has been so difficult to spot. The particle, which helps to explain how the universe got its mass, was first predicted in 1964 but it wasn't until this year that the European Organization for Nuclear Research (CERN) announced it had been able to detect it. On 27 November two physicists who had been key in developing the theory behind the boson - professors Peter Higgs from the UK and François Englert from Belgium - visited the EP.
The two prominent researchers were at the Parliament to take part in a lecture on unlocking the secrets of the universe, organised by the EP's Science and Technology Options Assessment Unit (STOA). We took the opportunity to ask them a few questions. Check out our infographic to find out more about the Higgs boson itself.
Is the boson the end of the road for particle physics? What is it that has made the boson so famous, other than its slightly odd nickname? How does one become a physicist? Can research exist at a time of austerity? As one would expect, the answers weren't always straightforward, except for one: cutting research budgets would be "unwise", as Mr Higgs put it.
Although the Higgs boson has now been discovered, it certainly does not mean that there is nothing left to explain in particle physics. "We are far from the end of knowledge," said Mr Englert and Mr Higgs agreed there was still hope of solving the puzzle of dark matter, which makes up more than 90% of the universe. Yet, he added: "What has been found at CERN looks like so much a good fit to the simplest version of the theory of the standard model that it isn't providing any hints of what might come next."
The search for the God particle managed to catch the media's attention. How come? "The CERN PR department did its job well," joked Mr Higgs, but in truth, both seemed a little perplexed by the sudden notoriety of the boson. "It is clear that a breakthrough in our understanding of the universe fascinates," said Mr Englert, adding that Einstein's theory of space-time curvature had a tremendous impact when it was first presented a century ago.
We asked Professor Higgs, the son of a BBC electrical engineer, what brought him to theoretical physics and he explained that he also considered engineering but discovered that "my inclinations were not so practical". He added that attending the same Bristol school as legendary Anglo-Swiss physicist Paul Dirac certainly helped: "I started to ask, 'what has this guy done', and I learnt something about quantum theory."
America dominated science in the 20th century. However, as Mr Englert explained: "If you mean it's about having the best tanks or bombs then you can say so, but as far as fundamental research is concerned, I think things have shifted. There is nothing in the US comparable to CERN." Mr Higgs added: "CERN is the lead institute and that is partly due to the peculiarities of the American political system and their funding of science." He said Congress cancelling the proposed Texas super collider back in the 1990s because of its cost was "very unfortunate", adding: "I don't think the American scientific community has really recovered from that experience." Mr Englert said: "It's not imaginable with the money invested in the US that a discovery comparable to the discovery made at CERN could be made there."
Money is certainly crucial to making science possible. Due to the crisis, there has been much talk of potential cuts to European research budgets. Mr Higgs said any such move would be unwise if only because of the spin-offs in terms of technological development. Or as Mr Englert put it, it'd be "a catastrophe".
Professor Higgs and Professor Englert also participated in a chat with EP fans on Facebook. For the full text of the chat, click on the link on the right.